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// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package reverseproxy
import (
"encoding/json"
"fmt"
"net/http"
"github.com/caddyserver/caddy/v2"
)
func init() {
caddy.RegisterModule(adminUpstreams{})
}
// adminUpstreams is a module that provides the
// /reverse_proxy/upstreams endpoint for the Caddy admin
// API. This allows for checking the health of configured
// reverse proxy upstreams in the pool.
type adminUpstreams struct{}
// upstreamResults holds the status of a particular upstream
type upstreamStatus struct {
Address string `json:"address"`
NumRequests int `json:"num_requests"`
Fails int `json:"fails"`
}
// CaddyModule returns the Caddy module information.
func (adminUpstreams) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "admin.api.reverse_proxy",
New: func() caddy.Module { return new(adminUpstreams) },
}
}
// Routes returns a route for the /reverse_proxy/upstreams endpoint.
func (al adminUpstreams) Routes() []caddy.AdminRoute {
return []caddy.AdminRoute{
{
Pattern: "/reverse_proxy/upstreams",
Handler: caddy.AdminHandlerFunc(al.handleUpstreams),
},
}
}
// handleUpstreams reports the status of the reverse proxy
// upstream pool.
func (adminUpstreams) handleUpstreams(w http.ResponseWriter, r *http.Request) error {
if r.Method != http.MethodGet {
return caddy.APIError{
HTTPStatus: http.StatusMethodNotAllowed,
Err: fmt.Errorf("method not allowed"),
}
}
// Prep for a JSON response
w.Header().Set("Content-Type", "application/json")
enc := json.NewEncoder(w)
// Collect the results to respond with
results := []upstreamStatus{}
// Iterate over the upstream pool (needs to be fast)
var rangeErr error
hosts.Range(func(key, val interface{}) bool {
address, ok := key.(string)
if !ok {
rangeErr = caddy.APIError{
HTTPStatus: http.StatusInternalServerError,
Err: fmt.Errorf("could not type assert upstream address"),
}
return false
}
upstream, ok := val.(*Host)
if !ok {
rangeErr = caddy.APIError{
HTTPStatus: http.StatusInternalServerError,
Err: fmt.Errorf("could not type assert upstream struct"),
}
return false
}
results = append(results, upstreamStatus{
Address: address,
NumRequests: upstream.NumRequests(),
Fails: upstream.Fails(),
})
return true
})
// If an error happened during the range, return it
if rangeErr != nil {
return rangeErr
}
err := enc.Encode(results)
if err != nil {
return caddy.APIError{
HTTPStatus: http.StatusInternalServerError,
Err: err,
}
}
return nil
}
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